AP BIOLOGY

Detailed explanation-1: -A concentration gradient occurs when the concentration of particles is higher in one area than another. In passive transport, particles will diffuse down a concentration gradient, from areas of higher concentration to areas of lower concentration, until they are evenly spaced.

Detailed explanation-2: -The difference in the concentration of molecules across a distance is call the concentration gradient. molecular collisions that result from the movement cause the molecules to move from areas where they are highly concentrated.

Detailed explanation-3: -Moving against a concentration gradient means that the substance is moving from a low concentration to a high concentration. Moving down (descending) a concentration gradient means that the substance is moving from high concentration area to a low concentration area.

Detailed explanation-4: -The difference in the concentration of a substance between two areas is called the concentration gradient . The bigger the difference, the steeper the concentration gradient and the faster the molecules of a substance will diffuse. The direction of diffusion is said to be ‘down’ or ‘with’ the concentration gradient.

Detailed explanation-5: -In passive transport, particles (e.g. ions or molecules) are transported along the concentration gradient. This means that the particles move from areas of high concentrations to areas of low concentrations. Because of the passive movement of particles no chemical energy is spent as it takes place.